Connector and electrical connection device

A connector that is to be fitted to a partner connector, comprising:

• a housing that has an opening that opens in a direction that is opposite a fitting direction in which the connector is fitted to the partner connector;
• a cover that includes a first cover engagement part that engages with a housing engagement part that is formed on the housing, and is fixed to the housing so as to cover the opening;
• a slider that is housed within the housing, is provided so as to be slidable along the housing in a sliding direction that is a direction that intersects the fitting direction, and is configured to slide in the sliding direction so that the housing is fitted to the partner connector;
• an operation-target part configured to slide the slider upon being operated;
• and
• a lock mechanism that includes a slider engagement part that is formed on the slider, and a second cover engagement part that is formed on the cover, and is configured such that the slide engagement part engages with the second cover engagement part in a situation where fitting of the housing and the partner connector to each other is complete, so that the cover is prevented from being separated from the slider.